.APP_develop {
    width: 1350px;
    background-color: #f5f5f5;
    margin: 0 auto;
   
    .APP_develop_content {
        .APP_develop_title
        {
            b {
                font-size: 11px;
                color: #3f3f3f;
            }
            h1 {
                text-align: center;
                margin-top: 60px;
            }
           
            p {
                font-weight: 500;
                display: block;
                width: 788px;
                font-size: 14px;
                color: #999999;
                margin: 0 auto;
                text-align: center;
                margin-top: 5px;
            }
        }
       .APP_develop_content_list {  
           background-color: white;
           display: flex;
           margin-top: 12px;
           flex-direction: column;           
           img {
               &:first-child {
                   margin: 0;
               }
               flex: 1;
               margin-top: 15px;
           }
           .APP_develop_listnav {
            padding: 0 0 100px 0;
            ul {
                margin-top: 35px;
                width: 230px;
                margin: 0 auto;
                li  {
                    &:first-child {
                        border: none;
                    }
                    cursor: pointer;
                    border: 1px solid #999;
                    margin-top: 30px;
                    display: inline-block;
                    width: 38px;
                    height: 30px;    
                    line-height: 30px;
                    font-size: 16px;
                    text-align: center;
                }
            }
           }
       }
        
      
    }
}